The problem of reading separate lines of information of a type appearing in computer printouts, telephone directories, stock exchange quotations and the like is known. U.S. Pat. No. 3,739,739, granted June 19, 1973 to Roy J. Brase, for example, discloses an instrument for facilitating such reading in the form of a pair of laminated strips of synthetic resinous material in which areas of tinted and non-tinted material are juxtaposed to define guides which may be alined with a desired row of characters for isolating individual lines of data.
While such devices are of acknowledged utility where a large amount of such scanning is performed, many persons require an instrument of this general type for use at relatively infrequent intervals, and in which the cost of manufacture is considerably lower owing to economies in design and manufacture.